Existing technology for cracking and shelling various types of nuts is well known within the art, including devices ranging from simple manual tools which resemble specialized pliers, to sophisticated motorized systems suitable for high-volume product yield.
The first substantial problem to be addressed by most mechanical and automated systems is the problem of applying force to a nut with enough magnitude to crack the shell, while leaving the meat of the nut undamaged or uncrushed. To further complicate this problem, nuts to be shelled are of varying size, so a cracking chamber which holds a nut must accommodate a variety of shapes and sizes of nuts. Additionally, as the nut is cracked, shards or pieces of shell material may be ejected from the cracking chamber, producing a potential safety hazard for the operator, an undesirable mess in the work area, and a potential reliability problem for the device if the shell fragments enter the workings of the mechanism.
Existing tools for meeting all of these needs have been either extremely simple, manually operated systems, or fairly complex automated systems. The device disclosed in U.S. Design Pat. No. 298,099 to Luc is an example of the former type of simple, manual tool. While simple manual tools such as this one allow precise cracking of the shell with minimized damage to the meat coupled with a reliable mechanism, this tool is not particularly well suited for higher-volume cracking operation.
Motorized systems of the latter type, such as those disclosed in U.S. Pat. No. 4,603,624 to Greenblatt; U.S. Pat. No. 5,711,213 to Thomson (Kirk); and U.S. Pat. No. 5,505,123 to Kim are suitable for higher volume applications, but may also exhibit higher failure rates and cost of operation due to the complexity of the mechanism.
A number of nut cracking devices, especially those which are lever-actuated, are known which address the needs and issues of medium-volume nut crackers. Devices such as those disclosed in U.S. Pat. No. 4,377,970 to Kenkel and U.S. Pat. No. 4,438,687 to McNiel provide simpler mechanisms with higher volume capabilities, but may still exhibit problems with adjustment to varying nut sizes without undesired nut meat damage, and may still exhibit safety problems with flying shell pieces.
Therefore, there exists a need in the art for a nut cracking device suitable for moderate volume nut cracking operation, with better reliability and serviceability due to improved mechanical system design, operable by a single operator, and which provides improved handling of varying sizes of nuts while providing enhanced safety for the operator.